A037589 - OEIS

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A037589

Decimal expansion of a(n) is given by the first n terms of the periodic sequence with initial period 3,1.

3, 31, 313, 3131, 31313, 313131, 3131313, 31313131, 313131313, 3131313131, 31313131313, 313131313131, 3131313131313, 31313131313131, 313131313131313, 3131313131313131

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OFFSET

1,1

LINKS

Table of n, a(n) for n=1..16.

Index entries for linear recurrences with constant coefficients, signature (10,1,-10).

FORMULA

G.f.: x*(3+x)/(1-10*x-x^2+10*x^3). - Jaume Oliver Lafont, Mar 24 2009

MATHEMATICA

Table[FromDigits[PadRight[{}, n, {3, 1}]], {n, 20}] (* Harvey P. Dale, Oct 19 2016 *)

CROSSREFS

Sequence in context: A113075 A111137 A037785 * A247351 A089289 A011545

Adjacent sequences: A037586 A037587 A037588 * A037590 A037591 A037592

KEYWORD

nonn,base,easy

AUTHOR

Clark Kimberling

STATUS

approved